X-type bearing



g- 19, 1952 w. MESSINGER 2,607,641

X-TYPE BEARING Filed March 2, 1949 I I 3027 20 a I INVENTOR.

I V/LA/AM Mia's/Nam BY l Patented Aug. 19, 1 952 infla es "AnimationMarch 2, 1949,"sri a1 No.'79;133

ensus. o1. cos ist) This invention 'relates to improvements inantifriction hearings. andv more'particularly. to im- ''-proved X-type.bearings suitable for use in sup- ---'-portin'g relatively rotatableelements of heavy.

duty machinery andthelike; .4

.1 i My Patent No.1, 2 130,359,: "dated; November .4,

- 1947, ..-discloses a typicaLX-typebearing inwhich angu1ar1y Lrelated.rollerswareiinterposed between singularly related-race surfacesinsuchga Way as to'opposeradial asswelliasaxial thrust... These 'X-type:bearings. have proven ,to be particularly satisfactory for resisting..heavy. thrust loads; for example, in the-journal boxes .of railway carsand the. like. They are also-veryssatisiactory forsupporting a rotatableelement against radial as Vwellras axially. directed.forces.v However,due .touthe. fact thatthere is some looseness; present sin-bearings ofthis type to keep the friction to a minimum, these. hearings have not,been entirely a satisfactory .for .use in precision mounted deviceswhich are, subjected to heavy.,load s,- forexarnple, .thezrotary .tablesof, heavy duty gbflling machines, theturrets ofgun mounts. and the-like.Due to citheplay. permitted by thesebearingschattering or .rrelative.movementin addition, to rotating movezment is permitted. so that thedesired-precision of operation cannot be; obt ined, 1 ,7

I. have discovered that the disadvantages ofmy ,atented hearings, when,used rfor supporting aheavy lo arise...from certa r hara ri ti.rlinherent in; such .he r ns$.-.- .T us. in iv d roll s o th hea in opeat etu e.;.wbsta ially coni a1 innerand o uter race surfaces, the

iffacefis' concave, So lon'g'ias the roller isparallel 'With' a'generatrix of each of ,these surfaces, no difiiculty is encounteredjfor the roller maintains j substantially line contact with each of" therace f surfaces.-' However. some k a l and the race, surface results.Ina'sn iuchthisv int contact is at about the crit'erpr theroller ,thecenter of. the racewayfthereis"no' tendency jorthe'r'ollerto bind,

The Sn" ation is'quite differentitvithj the contact between theciaerboncavconical...

Upon canting oi race surface and the roller.

sinner surface being. convex "smegma outerfsurthe roller, the surface.of'. he rollerl assumes the 1..pbsition or; a chord of .lthe. curvatureof ltheirace surface so that the forces acting on the roller areconcentrated at oppositeends of'the roller Un- 5 der ;or.'dinary...1oadcondiions, ,thei. fo;rce s .a1te. -,i n sufficient to produce a bindingof. the rollers, but, the. bearing is to, be preloade d order to.'eliminate,|p1ay in it, the end contact of the roller 7 with. the.race; surface may i. become sufiiciently "strong .to introduce strongirictiOhhlQrestraintto .the. ,rotationqof theosbearingaand even jammin"and'lockingofthe entirebearing....,v An object. of, the presentinvention is-,to provide an X-type bearin which can he preloaded.;to..:elirninate play. from itwithout causing the bearing to jam duringits operation. .7. V

A'furthernob jecti of, the invention iSIQLPIO- vide a relatively.frictionless Xj-,type,bearing -.which is', substantially chatterless' sothat it ca'n U-be .used in heavy .duty. machiner tojprovide. a

precision mount. for a rotary elernent, thereof,

.Otherobiects of the invention will bec Ind m- ..:paren,t fromithefollowing cdcscription of typical forms of bearings embodying thepresent invention...;.. V o a;

In accordance withthe.present.q,invention, I have modified the X,bearingsoftlie type disclosed in'rny Patent No. 2,430,359 by providinga t ransverse. .CIOWIL of. small magnitude on each of the outer racesurfaces,v thisc'rown orr..,curvature transversely :offtheracej surfacebeing. sufiicijent; to a. prevent concentration of, the load, exerted10.1 the :rollersattheir. ends, In this way, the,s1ight c ant- .ing.inherent in the. rollers can do no more than 1 produceline contact ofthe. roller with theouter Jracefisurface so. that the. stresses'are..We11.".disr. :tributed. and thereisno tendency to producefurtherzcanting of .the rollers. .c By providing such crowned racesurfaces on'ithe 40 butenb'e'aring. members, I am alsoenabled to2p're-.zload the be'arings,.,thereby eliminating play from them and makingthemmost useful for support= ing :radiaLand axial. loads even in heavy; dutymachinery and in precision, machineryi. the op'eration of which would beseriously afiected'iby w'play' or chatter in the bearing. -I accomplishthe prelo'ading of ."the'ibeai'ing by providing a splitv outer racememberiin the form of two separable rings each having a crovvn'ed racesurface thereon," these ringimem- 'bers being so designedthat'when'they' engage with 'the 'rollers of the bearing with" lightconta'ct; the-bearing rings are spaced slightly apart.

when: these rings are'forcertogetheriinterfaceto-face contact, theyexert pressure on the rollers or preload the rollers to a degreedependent upon the spacing between the ring elements. Such preloadingeffectively eliminates any play between the rollers and the racesurfaces in right-angularly related directions so that thrust loads andradial loads have no effect on the relawill compensate for wear on thebearing surfaces and the rollers.

For a better understanding of the presentinthe cylindrical surfaces ofthe rollers and the crowned surfaces 26 and 21. The amount of crown ofthe roller is, in most instances, very small. For example, in a typicalbearing, the

crown on the race surface may be on the order of one thousandth of aninch. This crown is, however, suflicient to prevent the rollers frommaking contact only at their ends with the race surfaces 26 and 21 ifthe rollers cant slightly in the cage 20. In this way, any tendency ofthe rollers to bind or jam against the" outer race surfaces 26 and 21 isprevented.

Another feature of my new bearing is the arrangement of the race rings2| and 22 so that vention, reference may be had to the accompanyingdrawings, in which:

Fig. 1 is an end view of a typical bearing assembly embodying thepresent invention;

Fig. 2 is a view in section through one'side of- Y member of the bearingwith some of the rollers removedtherefroma Referring now to Figs. 1 and2, a typical hearing assembly may be used to support a rotary sleeve orhollow shaft member H] in a fixed member The bearing assembly may beused in precision gun mounts, heavy duty milling and boring machineryand for any other purpose where relatively frictionless movement underload may be required.

As shown in Fig. 2, the bearing includes an inner race member I2 whichmay be seated against a houlder 3 in the shaft member l0 and retained inposition by means of a clamping ring M which secured by means of screwsI5 or the like. The race member I2 is provided with two angularlyrelated race surfaces It and H, which, as illustrated, may be inright-angular relotion-ship. Rolling against these race surfaces It andIl are sets of right-angularly related rollers l8 and I9 which aresupported in a cage member of a type more particularly disclosed anddescribed in my Patent No. 2,430,359.

The outer race member may be made up of two separable rings 2| and 22,one of these rings being mounted against a shoulder 23 on the supportingmember I I while the other is retained in position by means of aclamping ring 24 also secured to the member H by means 'of the screws25. The rollers l8 and I9 are of a greater diameter than their axiallengths so that clearance is afforded between the ends of the rollersand the surfaces in right-angular relation to the surfaces with whichthe rollers are in rolling engagement. The length of each roller |=8,for example, is less than the spacing between the surface 5 and the racesurface 26 on the ring member .22 by an amount at least equal to theelastic deformation of therace members and the rollers under load.Similarly, the length of each roller I9 is less than the spacing betweenthe race surface l1 and the race surface 21 on the ring member 2|. Thestructure described above is disclosed more particularly in my PatentNo. 2,430,359.

The novelty of my improved X-type bearing resides in the followingfeatures. As shown in Figs. 2 and 3, each of the race surfaces 26 and 21is slightly crowned so that when the race surfaces just engage thesurfaces of the rollers, point rings.

the bearing can be preloaded in order to eliminate play between therollers and the race members. This effect is attained by milling orotherwise forming the rings 2| and 22 so that a space 2'8-is leftbetween the rings 2| and 22 when these ringsware in light engagementwith the rollers l8 and I9. Also, the rings 2| and 22 are counterboredas at '29, and 30 in order. to increase the transverse flexibility ofthese rings.

When the bearing is put into service, the clamping ring 24 is screweddown to force the adjacent faces of the rings 2| and 22 together therebyclosing the gap or space 28 between the As the rings move inwardly, theyexert 1 pressure against the sides of the rollers, thereby preloadingthem and eliminating all play bebetween the rollers and the racesurfaces.v The space between the rings 2| and 22 may be variedsubstantially but a clearance in the vicinity of five or six thousandthsof an inch has proved to be satisfactory to obtain adequate preloadingof the bearings.

The pressure produced by forcing the rings 2| and 22 together producessome elastic indentation of the rollers and the race surfaces but notenough to impair seriously the action of the bearing. Some of thepressure results in flexing of the rings 2| and 22 for the reason thatthe counterb-ores 29 and 30 impart sufficient flexibility to the rings2| and 2-2 to permit them to dish slightly as shown in Fig. 3. Thisdishing or defiection of the rings 2=| and 22 stores resilient energy intime so that they act like springs maintaining an intimate contactbetween the rollers and the race surfaces even after the rollers andrace surfaces have worn away to a substantial extent. While I havedescribed the outer race ring as being split, it will be understood thatthe inner race ring can be split into two rings, instead. The outer racering will, however, in either structure, be provided with the crownedrace surfaces.

It will be understood that the above-described bearing. is useful formany purposes where high precision of support of a rotary member isrequired and where chatter in a bearing would result in inaccurateoperation of the machine in which the bearing is used. Therefore, my newbearing provides a very effective solution for the problem of producinga chatterless mount for a rotary element. It will be understood, ofcourse, that the size of the bearing may be varied substantiallydepending upon requirements, that the amount of crown of the surface andthe preloading of the bearing may also be modified in conformity withthe conditions under which the bearing is to be used. Therefore, theform of the bearing disclosed herein should be considered asillustrative and not as limiting the scopeof contact is provided betweenabout the centers of f QI l1 wing claims. g Y 7 I claim:

1. An X type roller bearing comprising an inner race member having apair of substantially right-angularly related conical race surfacesdefining a groove in the member, a plurality of angularly relate-d,cylindrical rollers in rolling engagement with each of the racesurfaces, each roller having a diameter greater than the length of theroller, an outer race member having race surfaces thereon facingdifferent race surfaces on the inner race member, the race surfaces onthe outer race member engaging the rollers in rolling engagement withthe facing race surfaces of the inner member, the race surfaces on theouter race member being crowned to make substantially point contact withthe rollers in engagement therewith at about their mid-portions, one ofthe race members being divided circumferentially to provide twoseparable rings which are spaced apart a few thousandths of an inch whenboth rings are in light contact with the rollers, and means to force therings substantial- 1y into engagement with each other to exert pressureon the rollers to preload the races and rollers and restrain the innerand outer race members against all relative movement except rotarymovement, each roller having substantially line contact with itsrespective crowned race when the roller is canted slightly and the racesand rollers are preloaded.

'2. The bearing set forth in claim 1 in which the rings are sufficientlyresilient to be deflected slightly by the pressure on the rollersthereby to exert resiliently applied pressure on the rollers.

WILLIAM MESSINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

